The present invention relates to a spherical joint comprised of a cup-shaped main supporting body with two spherical surfaces arranged concentrically, and an upper and a lower bearing body. The spherical joint can be utilized in the construction of suspension systems, steering systems, as well as in the construction of engine piston rods and piston bodies having a built in combustion chamber.
An important part of research and development work, particularly for vehicle construction, is concerned with the creation of a light and compact joint, capable of continuously compensating for wear and for deviation from concentricity.
In U.S. Pat. Nos. 4,347,014, 3,689,100 and 4,511,276, there is disclosed spherical joints which consist of a cup-shaped main supporting body, an upper bearing body and a lower bearing body. The upper and the lower bearing bodies are constructed so the concave surface of the cup-shaped main supporting body forms an external coupling with the convex surface of the upper bearing body which may be covered with an antifriction material, and the convex surface of the cup-shaped main supporting body forms an internal coupling with the concave surface of the lower bearing body which may be covered with an antifriction material. Such spherical joints have some disadvantages. For example, they are built primarily of massive bodies manufactured mainly by using traditional machining processes with high energy and material consumption, and compensate for wear only in the direction of the longitudinal axis. Further, they do not compensate for deviations from concentricity between internal and external couplers and none of them has forced lubrication. The failure to compensate for the wear in all planes or directions, and for deviations from concentricity, as well as absence of forced lubrication, results in the decrease in durability of this kind of joint.
In Romanian Patent No. 100,789, there is described a spherical joint used as a cylindrical joint for connecting the piston with the piston rod using a cup-shaped solid of revolution which is a part of the piston rod, peripherally concave and convex, forming external and internal couplers with the mating surfaces belonging to an upper bearing body being the bottom part of the combustion chamber and to a lower bearing body which is threaded to the skirt piston of the piston and is blocked in position with a nut. Such a spherical joint has the disadvantage of a massive construction using machining processes with a high energy and material consumption. Furthermore, they are not capable of compensating for wear and deviation from concentricity in any direction.